They do not focus you because you're not a problem, just some mosquito buzzing around. They are killing the players who are more of a threat rather than this tank build with no damage.
How did you just find 4 other melee players randomly? Also nobody used CC except the leap.
Because most of pvp build videos consist of footages featuring uncoordinated average joes that drop in few seconds. Very rarely there is a footage against a player that is above average, when you see and feel both sides take effort.